1. Field of the Invention
This invention relates to portable communication devices and more particularly to that class of apparatus which produces sound whilst providing protection to the head of the user.
2. Description of the Prior Art
The prior art abounds with sound producing helmets. U.S. Pat. No. 2,904,645 issued on Sept. 15, 1959 to G. A. Sarles teaches a radio device adapted to be attached to a head protecting helmet. The earphone portion of the apparatus is detachably engaged to the structural part of the helmet having portions of the earphone protected by a resilient rubber-like pad.
U.S. Pat. No. 3,586,977 issued on June 22, 1971 to H. V. Lustig wherein the disclosure describes a system providing voice intercommunication between a motorcycle rider and a passenger when both are wearing motorcycle helmets. The system employs a transistor radio with switching means to enable it to be used selectively for intercommunication purposes and for receiving radio broadcasts. The speaker portion of the apparatus is fixedly secured to the interior portion of the helmet.
U.S. Pat. No. 3,916,312 issued on Oct. 28, 1975 to W. L. Campbell teaches an improved portable voice communication device which comprises a speaker-microphone unit having a transducer-speaker disposed in a sealed housing and an elongated acoustical pick-up tube and an ear funnel communicating with opposite sides of the speaker and projecting from the housing. A radio transceiver is disposed in a second separate housing. The transceiver's signal converting section is electrically linked to the speaker-microphone unit through an elongated cable. Anchoring means attached to the exterior of the first housing adjacent the ear funnel cooperate therewith for releasably securing that housing in place adjacent the ear and mouth of the user on a helmet or headpiece. Pivoting or other movement of the first housing relative to the support device is prevented by the projecting ear funnel which engages an opening on the headwear.
All of the aforementioned patents suffer the common deficiency of utilizing speaker devices either projecting inwardly or outwardly from the innermost or outermost surfaces of the helmet thereby providing either a minimum amount of protection for the speaker device or in permitting such speaker devices to easily come into contact with portions of the user's body.